Knocks to the mat
I believe the answer is:
decks
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">knocks to the mat</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for decks that I've seen before include "Platforms on a vessel" , "Sets of cards" , "Packs of cards (US)" , "Embellishes" , "Packs of playing cards" .)